The values in the CMM Limits area of the Part/Machine tab in the Setup Options dialog box enables PC-DMIS to avoid collisions with the legs on Bridge-type CMMs during the calibration of tactile probes.
When you calibrate a tactile probe with long extensions, collisions may occur when the probe rotates in the different tip positions. To avoid collisions, you can enable the Leg Collision check. PC-DMIS runs the check online and just before the probe calibration routine. The Leg Collision check can automatically add safety movements.
When PC-DMIS connects to a supported Hexagon CMM (common controllers and FDC controllers), it automatically gets the CMM limits. You can manually edit the CMM limits. This can be useful if you do not have a Hexagon CMM. In addition, you might want to reduce the limits to avoid collisions with objects located within the machine volume (tool changers, fixtures, and so on).
To run the Leg Collision check, do the following:
If you need to modify or add the limits of the machine, enter the values in the X Min, Y Min, Z Min, X Max, Y Max, and Z Max boxes in the CMM Limits area.
Calibrate the probe tips. For details, refer to the "Calibrating Probe Tips" topic in the "Setting Up and Using Probes" chapter in the PC-DMIS CMM documentation.
To reset any modified values and obtain the CMM limits from your Hexagon CMM again, do the following:
Type 0 into the X Min, Y Min, Z Min, X Max, Y Max, and Z Max boxes.
Click OK to close the Setup Options dialog box.
Restart the measurement routine, or restart your machine.
Horizontal/Dual Arms
When you define the probe head orientation for a horizontal arm in the Part/Machine tab of the Setup Options dialog box, the CMM Limits area shows additional options:
Setup Options dialog box
This example is for Arm1, but you can press F5 to obtain the same for Arm2 in a dual arm system with the Arm2 active. This allows PC-DMIS to read the CMM limits from the Arm2 controller and populate the dialog box with the proper limits.
You can reduce the amount of CMM limits read in from the computer, for example, to exclude the area where a probe changer is mounted (typically in the -X direction). Press the Reset Limits button to reset the CMM limit values back to the original values from the controller.
PC-DMIS can draw the CMM limits in the Graphic Display window so you can get a visual idea of the setup.
The Define Tool Box button allows you to define an additional area that is taken into account by the legs collision engine during the calibration. This is seen in the case of horizontal/dual arm machines where the software uses multiple gauges oriented in Y and Z. In that case, the risk of collisions with the gauges and their support is different compared to Bridge machines, where typically there’s only one gauge oriented in Z+.
You can define that additional area by adding the gauges to a list. PC-DMIS then calculates the limits for the tool box to include them all. The defined tool box may or may not include the tool supports, in which case PC-DMIS extends the calculated tool box using the positions of the selected gauges to the lower limit of the CMM (-Z).
Example of defining the Tool Box for a Horizontal or Dual Arm system
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